Pumpjack lock

Abstract

A brake lock system for a pumpjack brake apparatus comprises a latch handle lever pivotally mounted at a location on a pumpjack, a countershaft rotatably mounted on the pumpjack, latch handle linkage, and control linkage that transitions movement and force of the latch handle lever to a latch arm with a latch dog for pivoting the latch arm to insert the latch dog in a notch in the pumpjack brake apparatus. The latch handle, latch handle linkage, control linkage, and latch arm have dimensions that provide a mechanical advantage of the latch handle lever over the latch arm.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A brake lock apparatus for a pumpjack, the brake lock apparatus comprising:
 a latch arm that is pivotally mounted on the pumpjack adjacent to a brake, the brake comprising a rotating component on a rotatable shaft of the pumpjack and a brake actuator mechanism, wherein the latch arm: 
 (i) is too high to be reachable by a person of ordinary adult height standing adjacent to the pumpjack without a ladder; and 
 (ii) has a latch dog protruding laterally from the latch arm such that pivotal movement of the latch arm in one direction engages the latch dog with a notch in a peripheral surface of the rotating component to prevent rotation of the rotating component and shaft and such that movement of the latch arm in the opposite direction disengages the latch dog from the notch in the rotating component; 
 a latch handle lever pivotally mounted at a location on the pumpjack that is within reach by a person of ordinary adult height standing adjacent to the pumpjack without a ladder for operation of the latch arm, wherein the latch handle lever is pivotal in a plane that is perpendicular to the shaft of the pumpjack, and the location of the latch handle lever on the pumpjack is also close enough to a brake lever on the pumpjack that operates the brake actuator mechanism of the brake to enable such person standing in such position adjacent to the pumpjack to reach and operate both the brake lever and the latch handle lever simultaneously; 
 a horizontal countershaft rotatably mounted on the pumpjack in a manner that allows the countershaft to be rotated about a horizontal longitudinal axis that is parallel to the shaft of the pumpjack and perpendicular to the plane in which the latch handle lever is pivotal; 
 a control linkage between the countershaft and the latch arm for transitioning the rotational motion of the countershaft to the pivotal movement of the latch arm; and 
 a latch handle linkage between the latch handle lever and the countershaft for transitioning the pivotal movement of the latch handle lever to rotational movement of the countershaft about the longitudinal axis of the countershaft, wherein the latch handle linkage includes a belt or chain connected to the latch handle lever and to the countershaft. 
 
     
     
       2. The brake lock apparatus of  claim 1 , wherein the belt or chain is connected to the latch handle lever by a first pulley or sprocket and to the countershaft by a second pulley or sprocket with the belt or chain extending over and between the first pulley or sprocket and the second pulley or sprocket. 
     
     
       3. The brake lock apparatus of  claim 1 , wherein the control linkage includes an additional belt or chain connected to the countershaft and to the latch arm. 
     
     
       4. The brake lock apparatus of  claim 3 , wherein the additional belt or chain is connected to the countershaft by a third pulley or sprocket and to the latch arm by a fourth pulley or sprocket, and wherein the additional belt or chain extends over and between the third pulley or sprocket and the fourth pulley or sprocket. 
     
     
       5. The brake lock apparatus of  claim 1 , wherein the latch handle linkage and the control linkage have dimensions that provide a mechanical advantage of the latch handle lever over the latch arm in a range of 1.5:1 to 8:1. 
     
     
       6. The brake lock apparatus of  claim 1 , wherein the latch handle linkage and the control linkage have dimensions that provide a mechanical advantage of the latch handle lever over the latch arm in a range of 1.75:1 to 4:1. 
     
     
       7. A brake lock apparatus for a pumpjack, the brake lock apparatus comprising:
 a latch arm that is pivotally mounted on the pumpjack adjacent to a brake, the brake comprising a rotating component on a rotatable shaft of the pumpjack and a brake actuator mechanism, wherein the latch arm: 
 (i) is too high to be reachable by a person of ordinary adult height standing adjacent to the pumpjack without a ladder; and 
 (ii) has a latch dog protruding laterally from the latch arm such that pivotal movement of the latch arm in one direction engages the latch dog with a notch in a peripheral surface of the rotating component to prevent rotation of the rotating component and shaft and such that movement of the latch arm in the opposite direction disengages the latch dog from the notch in the rotating component; 
 a latch handle lever pivotally mounted at a location on the pumpjack that is within reach by a person of ordinary adult height standing adjacent to the pumpjack without a ladder for operation of the latch arm, wherein the latch handle lever is pivotal in a plane that is perpendicular to the shaft of the pumpjack, and the location of the latch handle lever on the pumpjack is also close enough to a brake lever on the pumpjack that operates the brake actuator mechanism of the brake to enable such person standing in such position adjacent to the pumpjack to reach and operate both the brake lever and the latch handle lever simultaneously; 
 a horizontal countershaft rotatably mounted on the pumpjack in a manner that allows the countershaft to be rotated about a horizontal longitudinal axis that is parallel to the shaft of the pumpjack and perpendicular to the plane in which the latch handle lever is pivotal; 
 a control linkage between the countershaft and the latch arm for transitioning the rotational motion of the countershaft to the pivotal movement of the latch arm, wherein the control linkage includes a belt or chain connected to the countershaft and to the latch arm; and 
 a latch handle linkage between the latch handle lever and the countershaft for transitioning the pivotal movement of the latch handle lever to rotational movement of the countershaft about the longitudinal axis of the countershaft. 
 
     
     
       8. The brake apparatus of  claim 7 , wherein the latch handle linkage includes an additional belt or chain connected to the latch handle lever and to the countershaft. 
     
     
       9. The brake apparatus of  claim 8 , wherein the additional belt or chain is connected to the latch handle lever by a first pulley or sprocket and to the countershaft by a second pulley or sprocket with the additional belt or chain extending over and between the first pulley or sprocket and the second pulley or sprocket. 
     
     
       10. The brake lock apparatus of  claim 7 , wherein the belt or chain is connected to the countershaft by a third pulley or sprocket and to the latch arm by a fourth pulley or sprocket with the belt or chain extending over and between the third pulley or sprocket and the fourth pulley or sprocket. 
     
     
       11. The brake lock apparatus of  claim 7 , wherein the latch handle linkage and the control linkage have dimensions that provide a mechanical advantage of the latch handle lever over the latch arm in a range of 1.5:1 to 8:1. 
     
     
       12. The brake lock apparatus of  claim 7 , wherein the latch handle linkage and the control linkage have dimensions that provide a mechanical advantage of the latch handle lever over the latch arm in a range of 1.75:1 to 4:1.